U.S. patent number 6,914,414 [Application Number 10/442,241] was granted by the patent office on 2005-07-05 for cooling device for battery pack and rechargeable battery.
This patent grant is currently assigned to Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki Kaisha. Invention is credited to Takashi Asahina, Toyohiko Eto, Shinji Hamada, Ko Watanabe.
United States Patent |
6,914,414 |
Hamada , et al. |
July 5, 2005 |
Cooling device for battery pack and rechargeable battery
Abstract
In a battery pack including a plurality of prismatic
rechargeable batteries arranged in parallel with ventilation spaces
being provided therebetween, the battery pack is constituted so
that cooling air is downwardly sent from above the battery pack
through the ventilation spaces. In accordance with a temperature
detected with a temperature detection sensor attached to the lower
end of the rechargeable battery, a blower fan is controlled by a
control section. Moreover, a sensor placement concave, which is
separated from a space inside a battery case through a thin
partition wall, is provided on a bottom wall of the battery case of
the rechargeable battery. The temperature detection sensor is
placed in the sensor placement concave so as to be pressed against
the partition wall.
Inventors: |
Hamada; Shinji (Toyohashi,
JP), Asahina; Takashi (Toyohashi, JP), Eto;
Toyohiko (Toyota, JP), Watanabe; Ko
(Nishikamo-gun, JP) |
Assignee: |
Matsushita Electric Industrial Co.,
Ltd. (Osaka, JP)
Toyota Jidosha Kabushiki Kaisha (Aichi, JP)
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Family
ID: |
29766766 |
Appl.
No.: |
10/442,241 |
Filed: |
May 21, 2003 |
Foreign Application Priority Data
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May 22, 2002 [JP] |
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2002-148009 |
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Current U.S.
Class: |
320/107;
320/150 |
Current CPC
Class: |
H01M
50/20 (20210101); H01M 10/6557 (20150401); H01M
10/486 (20130101); H01M 10/6563 (20150401); H01M
10/613 (20150401); H01M 10/625 (20150401); H01M
10/647 (20150401); H01M 10/425 (20130101); H01M
50/209 (20210101); Y02E 60/10 (20130101) |
Current International
Class: |
H01M
10/42 (20060101); H01M 2/02 (20060101); H01M
10/50 (20060101); H02J 7/00 (20060101); H01M
10/04 (20060101); H01M 10/46 (20060101); H01M
010/46 () |
Field of
Search: |
;320/104,107,116,120,126,144,150,155 ;429/62,97,98,99,100,120 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2000-003734 |
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Jan 2000 |
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JP |
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2003142166 |
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May 2003 |
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JP |
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Other References
English Language Abstract of JP 2000-003734..
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Primary Examiner: Tso; Edward H.
Attorney, Agent or Firm: Greenblum & Bernstein,
P.L.C.
Claims
What is claimed is:
1. A cooling device for a battery pack including a plurality of
prismatic rechargeable batteries arranged in parallel with a
ventilation space being provided therebetween, the cooling device
comprising: a blower device that sends cooling air from above the
battery pack downwardly through the ventilation space to a lower
end of the batteries; and a control device that controls the blower
device in accordance with a temperature detected by a temperature
detection sensor attached to the lower end of at least one of the
rechargeable batteries.
2. A rechargeable battery comprising: a sealed prismatic battery
case that accommodates an electricity generating element, the
battery case having a sensor placement depression on a bottom wall
of the battery case through a partition wall thinner than the
bottom wall so as to be separated from a space inside the battery
case; and a temperature detection sensor provided in the sensor
placement concave and pressed against the partition wall.
3. The rechargeable battery according to claim 2, wherein the
temperature detection sensor includes a main body having a
detection portion, the main body being substantially fully received
within the sensor placement depression.
4. The rechargeable battery according to claim 3, wherein the
temperature detection sensor comprises the main body and
elastically deformable attachment arms extending from both sides of
the main body, the attachment arms having engaging portions at
their tips; and engaging protruding portions that extend from the
battery case and that engage with the engaging portions of the
attachment arms, the engaging protruding portions being provided on
a bottom of the battery case on two sides so that the main body is
pressed against the partition wall with the engaging portions of
the attachment arms being engaged with the engaging protruding
portions.
5. The rechargeable battery according to claim 4, wherein side face
depressions are provided at lower portions on the two sides of the
battery case; the engaging protruding portions are provided at
lower ends of the side face depressions so as not to protrude
beyond the two sides of the battery case; and the engaging portions
of the attachment arms are placed within the side face
depressions.
6. A battery system for rechargeable, prismatic batteries of a
battery pack, the battery system comprising: a temperature
detection sensor positioned at an end of a battery of a battery
pack that is opposite to an end of the battery pack in which a
blower device is positioned; and a control device that controls the
blower device, in accordance with a temperature detected by the
temperature detection sensor, to send air through a ventilation
space, the air being directed through the ventilation space from
the end of the battery pack in which the blower device is
positioned to the end of the battery pack at which the temperature
detection sensor is positioned.
7. The battery system according to claim 6, wherein the ventilation
space is provided between the batteries.
8. The battery system according to claim 6, wherein the temperature
detection sensor further comprises: a main body including a sensor
detecting part; and at least one arm extending from the main body,
the at least one arm having a portion that attaches to a battery
case.
9. The battery system according to claim 8, the battery system
further comprising: at least one depression positioned on a side of
the battery case, the at least one depression being configured to
receive the at least one arm of the main body to attach the
temperature detection sensor to the battery pack, whereby portions
of the arm do not protrude beyond the battery case on the side at
which the at least one depression is provided.
10. The battery system according to claim 8, wherein the main body
of the temperature detection sensor is pressed against a wall of
the battery case that is thinner than an adjacent wall of the
battery case, the main body being positioned within the battery
case such that the temperature detection sensor is configured to
detect temperatures of the battery.
Description
The present disclosure relates to subject matter contained in
priority Japanese Patent Application No. 2002-148009, filed on May
22, 2002, the contents of which is herein expressly incorporated by
reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cooling device for a battery
pack including a plurality of prismatic rechargeable batteries that
are arranged in parallel and to such a rechargeable battery.
2. Description of Related Art
In a conventional battery pack, in order to prevent decrease in a
battery output, charging/discharging efficiency, and battery
service life due to the elevation of the battery temperature by
heat generation that occurs along with charging/discharging, for
example, a fan is provided to send cooling air between cells in the
battery pack or between battery modules, each including a plurality
of serially connected cells.
The above-mentioned structure will be described with reference to
FIGS. 8 and 9. In FIG. 8, reference numeral 31 denotes a battery
pack serving as a power source for electric vehicles including
hybrid cars. In the battery pack 31, twenty to thirty rechargeable
batteries 32 are arranged in parallel with ventilation spaces 34
being provided between the respective rechargeable batteries 32.
The batteries 32 are interposed between a pair of end plates 35
that are provided on both ends of the rechargeable batteries 32 so
as to be integrally fixed therebetween, thereby constituting the
battery pack 31. As shown in FIG. 9, each of the rechargeable
batteries 32 is constituted as a battery module that is formed by
arranging a plurality of cells 33 in parallel in an integrated
manner and internally connecting the cells 33 in series. Each of
the cells 33 is constituted by housing an electrode plate group 33b
and an electrolyte solution in a battery case 33a. Connection
terminals 36 provided on both sides of the rechargeable batteries
32 are connected in series so as to obtain a predetermined output
voltage of the battery pack 31.
An air path 38 is provided in a support frame 37 for supporting the
battery pack 31, whereas an air exhausting path 39 is provided
above the battery pack 31. Reference numeral 40 denotes an air duct
for taking air inside a vehicle compartment so as to provide
cooling air through the air path 38. A blower fan 41 is provided in
the middle of the air duct 40. Reference numeral 42 denotes a
reflux duct for refluxing the cooling air exhausted from the air
exhausting path 39 into the vehicle compartment.
Temperature detection sensors 43 are attached to the upper ends of
the battery case 33a of appropriate cells 33 included in each of
the rechargeable batteries 32. Detection signals from the
temperature detection sensors 43 are input to a temperature
detection section 44 so as to detect a temperature of each of the
rechargeable batteries 32. Temperature data of each of the
rechargeable batteries 32 is input to a control section 45 which in
turn obtains a mean temperature of the rechargeable batteries 32.
The amount of cooling air created by the blower fan 41 is
controlled in accordance with the obtained mean temperature.
The attachment structure of each of the temperature detection
sensors 43 is as follows. As shown in FIG. 9, a temperature
detection hole 46, which is sealed from inside of the battery case
33a and is open to the exterior, is provided on the upper end of an
appropriate cell 33. The temperature detection sensor 43 is
inserted into the temperature detection hole 46 to be attached
through an adhesive or a resin, thermally fused, or fixed, thereby
allowing the detection of a temperature inside the cell from the
exterior of the cell.
The above-described cooling device for the battery pack employs an
upflow system for upwardly blowing cooling air from below the
battery pack 31. The cooling is controlled by detecting a
temperature of the cell with the temperature detection sensor 43
provided on the upper end of the rechargeable battery 32. However,
since heat generating portions such as the connection terminals 36
and joint portions 33c between the cells 33 concentrate in the
upper part of the rechargeable battery 32, this upper part has a
high temperature as compared with its lower part or the like.
Consequently, the upflow system is disadvantageous in that cooling
efficiency is impaired because a portion having a higher
temperature is cooled with cooling air having the lowered cooling
capacity and that a variation in temperature between the upper part
and the lower part of the rechargeable battery 32 is increased.
What is worse, in the upflow system, the air duct 46 or the like is
required to be provided in a largely devious manner so as to take
the air inside a vehicle compartment and to send it as shown in
FIG. 8. As a result, the cost is adversely increased, and the space
cannot be reduced due to the provision of the air duct 40.
In a case where a downflow system for allowing cooling air to
downwardly flow from above the battery pack 31, a temperature of a
portion of the cell having the highest temperature cannot be
detected because the temperature detection sensors 43 are attached
on the upper end of the rechargeable battery 32, that is the most
cooled portion.
SUMMARY OF THE INVENTION
In light of the above conventional problems, the present invention
has an object of providing a cooling device for a battery pack and
a rechargeable battery, which allow the battery pack to be
efficiently and uniformly cooled while achieving the reduction in
cost as well as in space, enabling the accurate control of a
battery temperature.
According to the present invention, a cooling device for a battery
pack including a plurality of prismatic rechargeable batteries
arranged in parallel with a ventilation space provided
therebetween, the cooling device includes: a blower device for
downwardly sending cooling air from above the battery pack through
the ventilation space; and a control device for controlling the
blower device in accordance with a temperature detected by a
temperature detection sensor attached to a lower end of the
rechargeable battery.
According to such a structure, since cooling air is downwardly sent
from above the battery pack through the ventilation space between
the rechargeable batteries, an upper part of each of the
rechargeable batteries where heat generating portions concentrate
is first cooled to efficiently cool the battery pack as a whole as
well as to restrain a variation in temperature between the upper
part and a lower part of the rechargeable battery. Although the
lower end of the rechargeable battery has the highest temperature
as a result of cooling in a downflow system, since the temperature
of the lower end of the rechargeable battery is detected by the
temperature detection sensor to control the blower device, a
temperature of the entire battery pack is regulated to be within an
appropriate range so as to prevent a decrease in a battery output,
charging/discharging efficiency, and battery service life.
Furthermore, since the downflow system is employed, an air duct for
cooling air is simplified in a case where air is taken from a
vehicle compartment so as to be sent as cooling air, thereby
reducing the cost and the space.
In a rechargeable battery according to the present invention,
including an electricity generating element housed in a sealed
prismatic battery case, a sensor placement concave is provided on a
bottom wall of the battery case through a partition wall thinner
than the bottom wall so as to be separated from a space within the
battery case. The temperature detection sensor is provided in the
sensor placement concave so as to be pressed against the partition
wall. A temperature of the lower end of the rechargeable battery,
which has the highest temperature in a case where the battery pack
is cooled in a downflow system, is thereby detected. Moreover,
since the temperature detection sensor is pressed against the thin
partition wall, a temperature inside the battery case is detected
with good accuracy and good response.
While novel features of the invention are set forth in the
preceding, the invention, both as to organization and content, can
be further understood and appreciated, along with other objects and
features thereof, from the following detailed description and
examples when taken in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the configuration of a cooling
device for a battery pack according to an embodiment of the present
invention;
FIG. 2 is a detailed longitudinal sectional view of a portion where
a temperature detection sensor is placed, according to the
embodiment;
FIG. 3 is a cross-sectional view taken along an arrow III--III in
FIG. 2;
FIGS. 4A and 4B are views showing the temperature detection sensor
in the embodiment, where FIG. 4A is a perspective view viewed from
above and FIG. 4B is a perspective view viewed from below;
FIG. 5 is a front view of a portion of a battery case where the
temperature detection sensor is placed, according to the
embodiment;
FIG. 6 is a bottom plan view of FIG. 5;
FIG. 7 is a cross-sectional view taken along an arrow VII--VII in
FIG. 5;
FIG. 8 is a schematic view showing the configuration of a
conventional cooling device for a battery pack; and
FIG. 9 is a front view including a partial longitudinal section of
a rechargeable battery in the conventional battery pack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of a cooling device for a battery pack
and a rechargeable battery constituting the battery pack according
to the present invention will be described with reference to FIGS.
1 to 7.
In FIG. 1, reference numeral 1 denotes a battery pack serving as a
power source for electric vehicles including hybrid cars. In the
battery pack 1, twenty to thirty rechargeable batteries 2 are
arranged in parallel with ventilation spaces 4 being provided
between the respective rechargeable batteries 2. The rechargeable
batteries 2 are interposed between a pair of end plates 5 provided
on both, ends of the rechargeable batteries 2 so as to be
integrally fixed therebetween, thereby constituting the battery
pack 1.
Each of the rechargeable batteries 2 is constituted as a battery
module that is formed by arranging a plurality of cells 3 in
parallel in an integrated manner and internally connecting these
cells in series. Each of the cells 3 is constituted by housing an
electrode plate group 3b and an electrolyte solution in a battery
case 3a. Connection terminals (not shown) provided in a protruding
manner on both sides of each of the rechargeable batteries 2 are
sequentially connected in series so as to obtain a predetermined
output voltage of the battery pack 1. The battery pack 1 is
supported by placing the end plates 5 on both ends and both ends of
each of the rechargeable batteries 2 which are vertical to the
paper plane onto a support frame 6 in a rectangular shape.
The upper face of the battery pack 1 is covered with a cover 7 with
a space being provided therebetween. An air path 8 is formed
between the upper face of the battery pack 1 and the cover 7. An
air duct 9 for taking air inside a vehicle compartment to provide
cooling air to the air path 8 is connected to one end of the air
path 8. In the middle of the air duct 9, a blower fan 10 is
provided. A bottom face cover 11 is provided for a portion of the
under face of the battery pack 1 that is surrounded by the support
frame 6, with a space being provided therebetween. An air
exhausting path 12 is formed between the under face of the battery
pack 1 and the bottom face cover 11. A reflux duct 13 for refluxing
cooling air after cooling the battery pack 1 into the vehicle
compartment is connected to one end of the air exhausting path
12.
A temperature detection sensor 14 is attached to a bottom wall of
the battery case 3a of an appropriate cell 3 of each of the
rechargeable batteries 2. A detection signal from the temperature
detection sensor 14 is input to a temperature detection section 15
so as to detect a temperature of each of the rechargeable batteries
2. Temperature data of each of the rechargeable batteries 2 is
input to a control section 16. The control section 16 in turn
obtains a mean temperature of the rechargeable batteries 2. In
accordance with the obtained mean temperature, the amount of
cooling air produced by the blower fan 10 is controlled.
Next, the arrangement configuration of the temperature detection
sensor 14 will be described in detail with reference to FIGS. 2 to
7. As shown in FIGS. 2 and 3, a sensor placement concave 19 is
formed in a bottom wall 17 of an appropriate battery case 3a so as
to be separated from a space inside the battery case 3a through a
partition wall 18 that is thinner than the bottom wall 17. The
temperature detection sensor 14 is placed in the sensor placement
concave 19 so as to be pressed against the partition wall 18.
The temperature detection sensor 14 includes a main body 20 having
a detection part 14a (see FIG. 2) therein; and elastically
deformable attachment arms 21, as shown in FIGS. 4A and 4B. The
attachment arms 21 are upwardly extended from both sides of the
lower end of the main body 20. Each of the attachment arms 21 has
an engaging portion 22 on its tip. The main body 20 is almost
entirely placed within the sensor placement concave 19, as shown in
FIGS. 2 and 3. A pair of terminals 23 are provided on one end face
20a of the main body 20 so as to protrude therefrom. A harness 24
for obtaining a detection signal is connected to the terminals
23.
On the bottom of the battery case 3a where the temperature
detection sensor 14 is placed, the sensor placement concave 19 is
formed in the bottom wall 17 as shown in FIGS. 5 to 7. At the same
time, side face concaves 25 are formed on both side faces at their
lower portions. At the central portions of the lower ends of the
side face concaves 25, engaging protruding portions 26 for engaging
with the engaging portions 22 of the attachment arms 21 are
provided so as not to protrude beyond both side faces of the
battery case 3a. The attachment arms 21 and the engaging portions
22 on their tips are constituted so as not to protrude beyond both
side faces of the battery case 3a while the engaging protruding
portions 26 are engaging with the engaging portions 22. In the
state where the engaging protruding portions 26 engage with the
engaging portions 22, the attachment arms 21 are elastically
deformed from a state indicated with a virtual line in FIG. 3 to a
solid line. The reaction force generated by the elastic deformation
presses the main body 20 against the partition wall 18.
On the bottom wall 17 of the battery case 3a, a leading groove 27
for externally leading the harness 24 is formed so as to be
continuous from one end of the sensor placement concave 19.
According to the configuration of this embodiment, since cooling
air is sent in a downflow system, that is, is downwardly sent from
above the battery pack 1 through the ventilation spaces 4 between
the rechargeable batteries 2, the upper portion of each of the
rechargeable batteries 2 where heat generating portions concentrate
is first cooled to perform the effective cooling. As a result, the
battery pack 1 is effectively cooled as a whole, and a variation in
temperature between the upper portion and the lower portion of the
battery pack 1 is restrained.
Moreover, the lower end of the rechargeable battery 2 has the
highest temperature as a result of cooling in a downflow system.
However, a temperature of the lower end is detected with the
temperature detection sensor 14 to control the blower fan 10 by the
control section 16, so that the entire battery pack 1 is controlled
to have a temperature within an appropriate range. Thereby, a
decrease in a battery output, charging/discharging efficiency, and
battery service life is prevented.
In addition, the sensor placement concave 19, which is separated
from the space inside the battery case 3a through the thin
partition wall 18, is provided in the bottom wall 17 of the battery
case 3a and the temperature detection sensor 14 is placed in the
sensor placement concave 19 so as to be pressed against the
partition wall 18. Consequently, in a case where the battery pack 1
is to be cooled in a downflow system, a temperature of the lower
end of the rechargeable battery 2 that has the highest temperature
is detected with good accuracy and good response while maintaining
the sealed state of the battery case 3a by the provision of the
partition wall 18.
Furthermore, since the main body 20 having the detection portion
14a therein is almost entirely placed within the sensor placement
concave 19, the temperature detection sensor 14 is scarcely
thermally affected by cooling air. Thus, a temperature is detected
with higher accuracy.
Moreover, the temperature detection sensor 14 is constituted by the
main body 20 and the elastically deformable attachment arms 21
having the engaging portions 22 on their tips. For attachment of
the temperature detection sensor 14, the engaging portions 22 are
engaged with the engaging protruding portions 26 provided on the
lower ends of the side face concaves 25 formed on both side faces
of the battery case at their lower portions with such a structure,
since the temperature detection sensor 14 can be easily attached to
and removed from the sensor placement concave 19, good operability
is obtained at the time of attaching the temperature detection
sensor 14 or at the time of maintenance such as replacement of the
rechargeable battery. Furthermore, the main body 20 is pressed
against the partition wall 18 due to elastic deformation of the
attachment arms 21, thereby achieving the temperature detection
with good accuracy.
Furthermore, since the engaging protruding portions 26 are provided
on the lower ends of the side face concaves 25 so as not to
protrude beyond both side faces of the battery case, and the
engaging portions 22 of the attachment arms 21 are constituted to
fit into the side face concaves 25, there is no portion protruding
beyond the side faces of the battery case with the temperature
detection sensor 14 being attached. Thus, cooling air flowing
through the ventilation spaces 4 is not hampered to allow high
cooling capacity to be maintained.
According to the cooling device for the battery pack of the present
invention, the upper part of each of the rechargeable batteries
where heat generating portions concentrate is first cooled. As a
result, the battery pack is efficiently cooled as a whole, and a
variation in temperature between the upper part and the lower part
of the battery pack is restrained. Moreover, since a temperature of
the lower end of the rechargeable battery, which has the highest
temperature as a result of cooling in a downflow system, is
detected with the temperature detection sensor so as to control the
blower device, a temperature of the entire battery pack is
controlled to be within an appropriate range to prevent a decrease
in a battery output, charging/discharging efficiency, and battery
service life. Furthermore, the structure of the air duct in the
cooling device is simplified, thereby reducing cost and space.
Furthermore, according to the rechargeable battery of the present
invention, in a case where the battery pack is cooled in a downflow
system, a temperature of the lower end of the rechargeable battery,
which has the highest temperature, is detected. In addition, since
the temperature detection sensor is in contact with the thin
partition wall by being pressed against it, a temperature inside
the battery case is detected with good accuracy and good
response.
Although the present invention has been fully described in
connection with the preferred embodiment thereof, it is to be noted
that various changes and modifications apparent to those skilled in
the art are to be understood as included within the scope of the
present invention as defined by the appended claims unless they
depart therefrom.
* * * * *